The invention relates to a method of authorizing external devices that can be optionally connected to a data bus of a motor vehicle. Via the method, at least a first code can be entered by an operator in an external device that can be connected with the data bus and is forwarded by this device to an authorization device of the motor vehicle via the data bus. The first code is compared with a second code by the authorization device and, if the first code corresponds to the second code, the device connected with the data bus is authorized to couple to the data bus.
New technologies and application scenarios in the automotive field often contain the coupling of external devices to a data bus of a motor vehicle. A common example is the coupling of a mobile telephone to a motor vehicle radio system.
By using modern network technologies (such as Bluetooth, WLAN), such a coupling of external devices can not only take place in a wire-line but also in a wireless manner.
In many cases, the range of such a wireless connection, in principle, also permits the coupling-on of external devices situated outside the motor vehicle. Therefore, in order to prevent an unauthorized and/or erroneous coupling of external devices, particularly in the case of the initial or first-time wireless coupling of an external device to a data bus suitable for the wireless coupling-on of external devices, the authorization of the external device for the coupling to the data bus has to be checked.
Methods for such an authorization are known, by which an external device, which can be connected with the data bus, is connected with the data bus and, by way of the data bus, sends a first code to an authorization device of the motor vehicle. The first code is compared with a second code by the authorization device. If the first code corresponds to the second code, the device connected with the data bus is authorized to be coupled to the data bus. In connection with the Bluetooth network technology, such an authorization method is usually called “pairing”.
In the context of this application, connecting an external device to a data bus means the establishment of a wire-line or wireless connection with at least one user of the data bus. The feasibility of a data communication between the external device and at least one user of the data bus for the purpose of implementing a certain functionality is not necessarily ensured by such a connection. Only a coupling of an external device to the data bus, in the context of this application, allows the carrying-out of a data communication between the external device and at least one user of the data bus for the purpose of the implementation of a certain functionality.
In the case of an authorization method of the above-described type, the first code typically has to be entered by the operator into the external device, which can be connected with the data bus. The input can take place, for example, by the selection of a certain menu item in the operating structure of the external device and a subsequent typing of the code on a keyboard of the external device.
The operator typically enters the second code into the motor-vehicle-side authorization device itself or into an input device of the motor vehicle assigned to the authorization device at least for this purpose. As a rule, also for carrying out such an input, the selection of a certain menu item in an operating structure and a subsequent typing of the code on a keyboard (or by way of a rotary button) is required.
Such a method has the disadvantage that the two codes have to be entered by the operator in two types of respectively high-expenditure and error-susceptible input processes. It is a particular disadvantage that the two input processes relate to two different devices—on the one hand, to the external device and, on the other hand, to the authorization device or an input device assigned to the latter.
As an alternative, it is known to fixedly store one of the two codes, particularly the second code, in the respective device. The operator can then typically find the respective code in written documentation, which is assigned to the respective device, and then has to only enter the code in the respective other device. Here, it is disadvantageous that the operator frequently does not immediately have access to the written documentation in the interior of the vehicle which, because of the code, are subject to certain secrecy requirements. In addition, the need to look-up information in written documents may be very time-consuming and/or is considered awkward by many operators. In the least favorable case, the written documents containing the code may even be lost.
The present invention provides a simple method of authorizing external devices, which requires the operator to enter only one code and does not call for any written recording of a code.
According to the invention, a method is provided for authorizing external devices that can be optionally connected with a data bus of a motor vehicle. At least a first code can be entered by an operator in an external device that can be connected with the data bus and is sent by this device, by way of the data bus, to an authorization device of the motor vehicle. The first code is compared with a second code by the authorization device and, if the first code corresponds to the second code, the device connected with the data bus is authorized to couple to the data bus. The second code is defined on the motor vehicle side independently of the external device. The second code is emitted by an output unit in the motor vehicle interior. Preferably, the second code is defined by the authorization device itself.
The method according to the invention has the advantage that the operator has to receive the second code defined on the motor vehicle side according to the invention only from the output unit by reading this second code, for example, from a graphic display unit and entering this second code as the first code in an external device to be authorized. The authorization of the external device will then require only a single input process to be carried out by the operator.
The invention is based on the consideration that although, in the case of a method of the above-mentioned type, the first code and the second code have to correspond to one another for a successful authorization of an external device, from a technical point of view, the common code in principle may be selected in any manner.
According to the invention, the second code is defined on the motor vehicle side at first independently of any external device. For a successful authorization of an external device to be authorized, only the same code then has to be entered into this device as the first code.
Since, as a rule, an operator in the vehicle interior is not expected to improperly couple an external device, the second code defined on the motor vehicle side can be made accessible to any vehicle occupant without any risk. According to the invention, the second code or a replacement code suitable for its determination is therefore emitted by an output unit in the motor vehicle interior.
A replacement code suitable for the determination of the second code is a code which is not identical with the second code but from which, possibly utilizing a corresponding prior knowledge, the second code can easily be derived by the operator. For example, for the determination of a four-digit second code, a replacement code having more than four digits, such as a six-digit replacement code, may be emitted to the operator. The operator can then derive the second code by using the prior knowledge that four selected digits of the replacement code form the second code.
For the correct detection of the second code and/or for its derivation from a replacement code and/or for triggering a corresponding output of an output unit, the operator's prior knowledge may be required. Providing such a prior knowledge to the operator may require a written recording of corresponding information, for example, in operating instructions. However, such a prior knowledge is much more easily remembered by most operators than a specific code itself, which is why a one-time recording of corresponding information is sufficient for most operators for having the corresponding prior knowledge in the target situation. In addition, such information is not vehicle-specific; in contrast to a code, it requires no secrecy and can easily be learned, for example, from the dealer or at a service facility.
The information as to how the second code defined on the motor vehicle side or a replacement code suitable for determining the second code can be fetched (or how the first code required for a successful authorization is obtained from the emitted replacement code) may possibly be added to a prompt of an external device emitted within the scope of the authorization process according to the invention for the input of a first code (or may be indicated by the prompt).
According to a preferred embodiment of the present invention, the second code is defined in a time-variable manner on the motor vehicle side. This, for example, has the additional advantage that attempts to spy on the code by unauthorized persons is made more difficult. Within the context of the present invention, a condition-dependent and/or situation-dependent defining is also considered to be a time-variable definition.
According to various embodiments of the invention, it may be necessary for the operator to carry out one or more operating actions in order to trigger an output of the second code by the output unit. It may, for example, be required to adjust an onboard computer to a certain display mode or to call up a certain menu item in the operating structure of a menu-based multifunctional operating system.
For the motor-vehicle-side defining of the second code, different methods are contemplated. For example, the second code may be determined from an operating quantity stored in the motor vehicle. In most cases, such a definition automatically necessitates a time variability of the second code.
The advantage of such an embodiment of a method according to the invention is that many operating quantities of the motor vehicle are stored in the motor vehicle anyhow and/or can be determined in a simple manner. In this case, it is advantageous that no special storage unit for storing the second code and/or no special devices and/or process steps for determining the second code have to be provided for the practical implementation of the invention. However, depending on the embodiment of the invention, a storage unit for storing the second code can deliberately be provided also without any absolute necessity.
In the case of a second code which is defined in a time-variable manner and is stored in a storage unit, the content of such a storage unit should be correspondingly updated in a time-controlled or event-controlled fashion.
According to a particularly advantageous embodiment of the invention, an operating quantity of the motor vehicle is used for determining the second code, which operating quantity can be emitted by an output unit of the motor vehicle for at least one additional purpose, particularly a purpose which is independent of the authorization of external devices. In the case of such an embodiment, the practical implementation of the invention can be carried out at particularly low expenditures because neither an output unit specific to the invention, nor a possibility for the output of the second code or of a replacement code has to be created which is specific to the invention.
According to preferred embodiments of the invention, the second code defined on the motor vehicle side or a replacement code suitable for its determination is made accessible to the operator in a manner that is as comfortable as possible. According to a particularly preferred embodiment of the invention, the second code or a corresponding replacement code is emitted by an output unit in the motor vehicle interior without the necessity of an operating action by the operator.
In particular, it is contemplated that the second code is determined by the authorization device from the mileage of the motor vehicle. The mileage, which, at least during the operation of the motor vehicle, typically is within the operator's field of view, is then used by the operator for determining the second code. No operating action by the operator is required for its output.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.